Effectiveness of seat belts in automobiles

Studies in other countries have demonstrated that properly worn seatbelts dramatically reduce the likelihood and seriousness of injuries in motor vehicle accidents. However, in the western region of Mexico, they are very rarely worn, due to the erroneous belief that its use does not protect, and may even harm its wearer. In order to ascertain its benefit or lack of it, we undertook a survey, comparing the degree of severity of lesions sustained, as well as the mortality, between a group of 15 patients who wore seatbelts and another of 35 patients who did not wear them; all patients were treated at the Emergency Room of the Hospital de Especialidades del Centro Médico de Occidente, after suffering car accidents. Among the first group, only one patient required hospitalization and there were no deaths. In the second group, all 35 patients had to be hospitalized, eight had sequelae and nine died. We conclude that seatbelts effectively protect the wearer against death and limit the severity of the injuries suffered during car accidents. We propose that educational campaigns to convince the public as to the benefits of its use should be carried out, and after a reasonable interval its use should be mandated by law.     

Occult carotid artery injury related to automobile seat belts

A 24-year-old woman had a clinically occult injury of the carotid artery from the shoulder seat belt restraint in a motor vehicle accident. Acute thromboembolism and hemiplegia occurred two hours after her admission to the emergency department. There were contusions of the neck and chest (seat belt sign) but no associated injuries of the cervical spine, mandible, larynx, or brachial plexus. The diagnosis was made by carotid arteriography after the occurrence of thromboembolism. Early clinical suspicion, diagnosis, and surgical repair of the artery are necessary to prevent delayed or recurrent thromboembolism and stroke. Carotid artery and duodenal injuries in this patient were related to improperly fitting seat belts. The current useful preventive measures are adjustment of seat belts to individual body habitus and the regular use of snugly adjusted belts.     

Incomplete Use of Condoms: The Importance of Sexual Arousal

The purpose of this study was to identify associations between incomplete condom use (not using condoms from start to finish of sex) and sexual arousal variables. A convenience sample of heterosexual men (n = 761) completed a web-based questionnaire. Men who scored higher on sexual arousability were more likely to put a condom on after sex had begun (AOR = 1.58). Men who reported difficulty reaching orgasm were more likely to report removing condoms before sex was over (AOR = 2.08). These findings suggest that sexual arousal may be an important, and under-studied, factor associated with incomplete use of condoms.     

Condoms and sexual behaviour of young tourists in Copenhagen

Sleep-in is a summer youth hostel in the center of Copenhagen with 459 beds, which was used for 19,296 overnight stays in July and August 1987. In the summer of 1987, each of the guests, 95% of whom were young tourists, received an envelope with a condom and a written reminder about the use of condoms during sexual relationships. During a period of the summer, 1,229 guests (498 women and 731 men) completed a questionnaire. The results showed that 21% of the men always, and 43% never had condoms in their luggage when travelling and 6% of the women always, and 79% never had condoms in their luggage. Of the 40 men who had sexual contact with Danish girls, 19 had always used a condom. Of the nine men with Danish homosexual contacts, three had always used condoms. Of the four women who had sexual contact with Danish men, none had used condoms.     

Multiple myeloma and chronic lymphocytic leukemia: parallels and contrasts.

Multiple myeloma (MM) and chronic lymphocytic leukemia (CLL) are closely related B-cell cancers. Parallel and divergent features of these diseases are reviewed. In MM, expression of multiple hemopoietic lineage-associated antigens on the malignant cells and the substantial likelihood of progression to acute myelogenous leukemia suggest transformation of a pluripotent stem cell. In CLL, transformation more likely involves a committed B-cell progenitor. Another difference is that clonal evolution with associated cytogenetic progression is common in MM but not CLL. Other data, including studies of proto-oncogenes and tumor suppressor genes, suggest that MM results both from increased proliferation and accumulation of tumor cells, whereas tumor cell accumulation is the predominant feature of CLL. These differences may be reflected in the seemingly greater role of cytokine abnormalities in MM progression. For example, osteoclast-activating properties of some cytokines account for bone involvement in MM but not in CLL. MM and CLL share common features such as stage-dependent anemia and immune deficiency. Both diseases respond to alkylating agents but vary markedly in their sensitivity to fludarabine (CLL greater than MM) and glucocorticoids (MM greater than CLL). Differences between these diseases in progression-free interval and survival may reflect different definitions of premalignant and malignant phases rather than biologic differences. Detailed comparisons between MM and CLL may provide additional insights into these and related B-cell cancers.     

Lymphatic filariasis: parallels between the immunology of infection in humans and mice

Mouse models of Brugia infection have provided much useful quantitative and qualitative information on the immune response elicited by different life cycle stages of filarial worms. Many parallels exist between the immune response in the mouse and the infected human and in this review we highlight areas of topical interest, including the induction of specific cytokine responses and their role in immunomodulation and protective immunity. These studies have reinforced the concept that different life cycle stages of filarial parasites each have their own mechanism of modulating responses so that potentially inflammatory IFN-gamma responses are downregulated. While the precise mechanisms of protective immunity remain to be defined, studies in the mouse have suggested novel pathways, including a possible role for granulocytes.     

Obesity: lessons from evolution and the environment

The 9th Stock Conference acknowledged the complex background of genetic, cultural, environmental and evolutionary factors of obesity. Gene–environment interactions underlie the flexibility in body‐weight and body‐fat regulation, illustrated by the hunter‐gatherers' feast and famine lifestyle, the variation in physical activity over the lifespan being highest at reproductive age, the variation in energy intake through ‘eating in the absence of hunger’, while running the risk of exceeding the capacity of triacylglyceride storage, leading to lipotoxicity and metabolic problems. Perinatal metabolic programming for obesity via epigenetic changes in response to a ‘Western diet’ results in production of lipid‐poor milk and metabolically efficient pups, contributing to the perpetuation of obesity throughout generations. Evolutionary insight from comparative physiology and ecology indicates that over generations activity‐induced energy expenditure has remained the same compared to wild mammals, that energy balance might be dependant on protein balance, while the function of taste changed from detection of poison or energy to social drinking and social behaviour. At present, the impact of assortative mating on obesity prevalence is unambiguously positive. The complexity that appeared can only be fully appreciated by setting the data into the context of our evolutionary history.     

Social interaction shapes babbling: testing parallels between birdsong and speech

Birdsong is considered a model of human speech development at behavioral and neural levels. Few direct tests of the proposed analogs exist, however. Here we test a mechanism of phonological development in human infants that is based on social shaping, a selective learning process first documented in songbirds. By manipulating mothers' reactions to their 8-month-old infants' vocalizations, we demonstrate that phonological features of babbling are sensitive to nonimitative social stimulation. Contingent, but not noncontingent, maternal behavior facilitates more complex and mature vocal behavior. Changes in vocalizations persist after the manipulation. The data show that human infants use social feedback, facilitating immediate transitions in vocal behavior. Social interaction creates rapid shifts to developmentally more advanced sounds. These transitions mirror the normal development of speech, supporting the predictions of the avian social shaping model. These data provide strong support for a parallel in function between vocal precursors of songbirds and infants. Because imitation is usually considered the mechanism for vocal learning in both taxa, the findings introduce social shaping as a general process underlying the development of speech and song.